Surface condenser

Surface condenser

The surface condenser is most commonly used as a shell and tube heat exchanger, or a shell and tube heat exchanger . It refers to a condenser that separates the condensed substance and the coolant with a heat transfer partition, and exchanges heat through the partition wall surface (called the heat transfer surface). The working principle is that when the secondary steam is in contact with the surface cooler, there is a temperature difference between the surface of the cooler and the secondary steam. According to the principle of heat transfer, the heat of the secondary steam will be transferred to the refrigerant in the cooling tube through the surface of the cooler. , so that the temperature of the secondary steam can be reduced. When the surface temperature of the cooler is lower than the dew point temperature of the treated secondary steam, the water vapor in the secondary steam is condensed to achieve the purpose of cooling and dehumidification. Surface condenser is used in the vacuum system in the evaporation device of chemical production, and the vacuum degree can reach -94KPa. The finished product is used in the vacuum system of the solid alkali evaporation plant and belongs to the tube and tube heat exchanger. In the production process, forming a vacuum by condensing secondary steam is an effective method to reduce the boiling point of lye and reduce steam consumption. The secondary steam enters the shell side of the heat exchanger and exchanges heat with the cooling water in the tube side to form a vacuum, and the non-condensable gas is pumped out by the vacuum pump

Specification of surface condenser

The specification of a surface condenser for solid caustic soda evaporation will depend on several factors, including the required vacuum level, the operating temperature, and the amount of steam being condensed.

Generally, the condenser should be designed with sufficient heat transfer area to handle the amount of steam being condensed, while also being able to maintain the desired vacuum level. The materials of construction should also be carefully chosen to ensure compatibility with the process fluids and to prevent corrosion.

Here are some key specifications that are considered for a surface condenser in solid caustic soda evaporation:

• Vacuum level: The condenser should be capable of achieving a vacuum level of at least -94 kPa, which is the typical operating pressure for solid caustic soda evaporation.
• Heat transfer area: The heat transfer area of the condenser will depend on the amount of steam being condensed, as well as the desired cooling water temperature. A higher cooling water temperature will require a larger heat transfer area.
• Materials of construction: The condenser should be constructed from materials that are compatible with the process fluids and that can withstand the operating temperature and pressure. For solid caustic soda evaporation, materials such as titanium,  or nickel are suitable.
• Design pressure: The condenser should be designed to withstand the maximum pressure that is encountered during operation.
• Fouling resistance: The condenser should be designed to minimize fouling and scaling, which can reduce the heat transfer efficiency and increase maintenance requirements. This may involve the use of specialized tube designs or coatings.
• Drainage: The condenser should be designed to ensure proper drainage of condensate and any non-condensable gases that are present. This may involve the use of gravity drains or vacuum pumps.
• Maintenance: The condenser should be designed for easy maintenance and cleaning, with access to all tubes and headers. A cleaning system, such as a high-pressure water jet or chemical cleaning, may also be required to remove any fouling or scaling.

Surface condenser in caustic soda evaporation

The surface condenser can be used for caustic soda (sodium hydroxide) evaporation in a chemical manufacturing process. The process involves the following steps:

1. A solution of caustic soda and water is heated in an evaporator vessel to evaporate the water and concentrate the caustic soda.
2. The vapors generated during the evaporation process are then sent to the surface condenser.
3. The hot vapors come into contact with a bundle of tubes containing cooling water flowing through them in the surface condenser.
4. The vapors are cooled by the cooling water, causing them to condense into liquid on the surface of the tubes.
5. The condensed liquid is collected at the bottom of the surface condenser and pumped back to the evaporator vessel as a recycled stream.
6. The cooling water, which absorbs the heat from the vapors, is then circulated through a cooling tower or other heat exchanger to remove the heat and lower its temperature.
7. The cooled water is then recirculated back to the surface condenser to repeat the process.

By using a surface condenser in the caustic soda evaporation process, the energy consumption can be reduced, and the efficiency of the overall process can be improved. Additionally, the use of a surface condenser can also help to reduce the amount of caustic soda lost during the process, resulting in cost savings.